什么是“值”数组？

In C, the idea of an array is very straightforward—simply a pointer to the first element in a row of elements in memory, which can be accessed via pointer arithmetic/ the standard array[i] syntax.

However, in languages like Google Go, "arrays are values", not pointers. What does that mean? How is it implemented?

In most cases they're the same as C arrays, but the compiler/interpreter hides the pointer from you. This is mainly because then the array can be relocated in memory in a totally transparent way, and so such arrays appear to have an ability to be resized.
On the other hand it is safer, because without a possibility to move the pointers you cannot make a leak.

Arrays in Go are also values in that they are passed as values to functions(in the same way ints,strings,floats etc.) Which requires copying the whole array for each function call.

This can be very slow for a large array, which is why in most cases it's usually better to use slices

Since then (2010), the article Slices: usage and internals is a bit more precise:

The in-memory representation of [4]int is just four integer values laid out sequentially:

Go's arrays are values.
An array variable denotes the entire array; it is not a pointer to the first array element (as would be the case in C).
This means that when you assign or pass around an array value you will make a copy of its contents. (To avoid the copy you could pass a pointer to the array, but then that's a pointer to an array, not an array.)
One way to think about arrays is as a sort of struct but with indexed rather than named fields: a fixed-size composite value.